Nozzle control valve for sandblasting and like spraying apparatus

ABSTRACT

A gate valve is interposed in the delivery line between a spray nozzle and a source of air under pressure, in an area of minimum flow velocity. A threaded opening through the valve body intercepts the valve slide and connects opposed coupling members which slidably confine the slide between them. In one embodiment the coupling members are a nozzle and a hose collar, and the slide is manually adjustable. In a second embodiment the coupling members are a pair of adapters which connect the valve between sections of the delivery line, and the valve slide is adjustable by a power unit driven by air under pressure from said source.

United States Patent Hehr et al.

Raymond E. Campbell, 1306 SE. 37th Ave., Milwaukie, Oreg. 97222 [221 Filed: Oct.l6,1970

21 App1.No.: 81,319

[52] U.S.Cl. ..51/l1,51/12,239/146, 239/586 [51] Int. Cl ...B24c 7/00 [58] Field of Search ..251/152, 326, 61,148, 25; 51/8-12; 239/146, 586

[451 Dec, 5, 1972 476,188 5/1892 Conner ..251/148 X 2,405,854 8/1946 Ruemelin ..51/12 X 799,808 9/1905 Thompson... ..51/12 1,599,817 9/1926 l-loevel 3,201,901 8/1965 Pauli ..51/12 3,070,924 l/1963 l-lastrup ..51/12 X 2,938,305 5/1960 Bipes ..51/12 Primary Examiner-Donald G. Kelly Attorney-Oliver D. Olson [5 7] ABSTRACT A gate valve is interposed in the delivery line between a spray nozzle and a source of air under pressure, in an area of minimum flow velocity. A threaded opening through the valve body intercepts the valve slide and connects opposed coupling members which slidably confine the slide between them. In one embodiment the coupling members are a nozzle and a hose collar, and the slide is manually adjustable. In a second embodiment the coupling members are a pair of adapters which connect the valve between sections of the delivery line, and the valve slide is adjustable by a power unit driven by air under pressure from said source.

7 Claims, 4 Drawing Figures PATENTEU E 5 I972 sum 1 or 2 Laverne F Hehr Raymond E.Campbel1 BY INVENTORS PATENTEDMC 1912 3.704.553

SHEET 2 0F 2 Laverne F Hehr Ragm 0nd E.Campb e11 BY INVEN :ORS

gen 1 NOZZLE CONTROL VALVE FOR SANDBLASTING AND LIKE SPRAYING APPARATUS BACKGROUND OF THE INVENTION This invention relates to sandblasting and like spraying apparatus, and more particularly to novel control means by which to start and stop the emission of air pressure spray through a spray nozzle.

Heretofore such emission control has been achieved by a shut-off gate valve located at the nozzle outlet, i.e. in the area of highest flow velocity. Such an arrangement precludes the use of certain type nozzles, such as those having radial ports; distorts the spray pattern from the nozzle; and when used to spray sand and other abrasive materials, causes excessive wear of the valve, requiring frequent replacement.

In the normal use of conventional sandblasting equipment, in which a shutoff valve is provided at the front end of the nozzle, it is required when shutting down the equipment to shut off the air compressor which pressurizes the container. The pressure within the container thus is allowed to bleed down, with corresponding loss of sand. Then, when it is desired to use the apparatus once again, time must be allowed for air pressure to be built up in the container. The loss of time incident to bleeding down and building up the air pressure within the container represents a significant loss of operation time.

SUMMARY OF THE INVENTION In its basic concept this invention provides a nozzle control for sandblasting and like spraying apparatus located in the air delivery line in an area of minimum flow velocity.

It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages of prior nozzle controls.

Another important object of this invention is to provide a nozzle control capable of use with all standard type nozzles without modification.

A further important object of this invention is to provide a nozzle control capable of operation from a remote position by air pressure provided by the apparatus, with minimum modification of the latter.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary plan view of a nozzle control valve embodying the features of this invention.

FIG. 2 is a fragmentary sectional view taken on the line 2-2 in FIG. 1.

FIG. 3 is an end elevation as viewed from the left in FIG. 1.

FIG. 4 is a foreshortened view in side elevation of sandblasting apparatus having incorporated therewith a nozzle control valve embodying the features of this invention.

Although the nozzle control valve of this invention may be utilized with a wide variety of types of spraying equipment, such as equipment for spraying cement mixtures, chemicals in liquid solution or suspension, it has particular utility with conventional sandblasting equipment. FIG. 4 illustrates a typical form of conventional sandblasting equipment.

Thus, the equipment illustrated in FIG. 4 includes a container 10 mounted for convenient mobility on a pair of laterally spaced wheels 12 which cooperate with a forward leg 14 to provide a tripod support. The output of an air compressor (not shown) communicates through the hose 16, shut-off valve 18, T-coupling 20, pipe 22 and union 24 with the bottom interior of the container. The container thus forms a source of air under pressure.

An opening in the upper portion of the container is removably closed by a pressure tight cover 26 and serves to introduce sand or other material into the container for ejection under air pressure through a spray nozzle 28.

The spray nozzle communicates with the interior of the container through a delivery line assembly which, in the embodiment illustrated, includes a length of flexible hose 30 connected at one end to the nozzle by fitting 32 and at the opposite end to one end of a hollow elbow 34. The opposite end of the elbow normally connects to one end of a delivery pipe 36 which extends downward slidably and rotatably through a pressure seal 38 into the container. A hand lever 40 is mounted pivotally on the container and is coupled through a pivoted link 42 to a universal connector 44 secured to the pipe. The hand lever thus functions to adjust the pipe vertically, for proper positioning of the lower end of the pipe within the container, and the universal connector accommodates axial rotation of the pipe relative to the link, to facilitate manipulation of the nozzle.

Referring now to the embodiment illustrated in FIGS. 1-3, the nozzle control valve includes a valve body 46 provided with an axial threaded bore throughout its length. A guide slot 48 extends through the valve body, substantially normal to the threaded bore, and slidably receives therethrough an elongated valve slide 50. The valve slide is provided with an aperture 52. In one position of adjustment of the slide the aperture registers with the threaded bore (FIG. 2). In another position of adjustment of the slide the aperture is displaced from the bore and the slide intercepts and closes the bore. These positions of the slide are determined by the abutment pins 54 and 56, respectively, which are secured adjacent the opposite ends of the slide for abutment against the corresponding sides of the valve body. The slide is moved between these positions of adjustment manually by hand.

A pair of coupling means is provided for interposing the valve slide 50 between the nozzle 28 and the air pressure container 10. In the embodiment illustrated in FIGS. 1-3, one of the coupling means comprises the standard external thread on the inlet end of a standard spray nozzle. This threaded end is threaded into the threaded bore of the valve body from the downstream end of the latter. The other coupling means comprises an externally threaded hose collar 58 which is threaded into the threaded bore of the valve body from the opposite, upstream end of the latter. The extendingend of the hose collar slidably receives therein one end of the high pressure flexible hose 30, which is secured therein by such means as the screws 60.

In the preferred embodiment best illustrated in FIG. 2, there is interposed between the inner end of the hose collar 58 and the valve slide 50 a resilient annular gasket 62 of rubber or other suitable material, and a metal washer 64. The washer is disposed adjacent the valve slide, with the gasket interposed between it and the adjacent end of the hose coupling. The nozzle and hose coupling are threaded into the bore sufficiently to bring the inner end of the nozzle and the washer into sliding engagement with the opposite surfaces of the valve slide. This sliding contact serves to restrict the passage of air under pressure radially outward between the slide and the nozzle and washer. By thus restricting the escape of air under pressure, sand or other material entrained in the air also is restricted from such passage. This minimizes jamming of the slide and wear of the adjacent surfaces.

The adjusted position of the nozzle and hose collar in sliding engagement with the slide may be secured releasably by such means as the set screws 66, 68 illustrated. Preferably these set screws are provided with inner tip ends of nylon or other relatively soft material which is capable of providing sufficient frictional grip on the threads to secure the adjustment, without damaging the threads.

It is to be noted (FIG. 2) that the inlet end of the nozzle is provided with a bore 28 which converges from the inlet end to smaller diameter at the outlet end and that the diameter at the inlet end is at least as large as the diameter of the bore of the hose collar 58 and the aperture 52 in the valve slide. Thus, the slide is positioned in an area of minimum flow velocity of air under pressure and sand or other material entrained therein. By positioning the valve slide in such area of minimum flowvelocity, minimum abrasion and wear of the slide results. Moreover, by positioning the valve slide upstream from the nozzle, any of the standard type nozzles may be utilized. Further, the nozzles may be interchanged without dissipating the air pressure in the container, merely by closing the valve slide before unscrewing the nozzle from the threaded bore of the valve body.

Referring now to FIG. 4 of the drawings, the nozzle control valve of this invention is shown in combination with the sandblasting apparatus described hereinbefore. Thus, the valve body 46 is interposed between the elbow 34 and pipe 36 by means of the threaded coupling adapters 70 and 72, in manner similar to the threaded nozzle and hose collar previously described.

Power means is provided for reciprocating the valve slide 50. In the embodiment illustrated the power means comprises an air motor of the diaphragm type. Thus, a flexible diaphragm 74 divides a hollow motor housing 76 into a pair of opposed air chambers 78 and 80. An elongated output shaft 82 is secured to the diaphragm and extends forward through the chamber 78 and housing for connection to the extending end of the valve slide 56, by such means as the coupling 84. A resilient spring 86 is positioned in the opposite chamber 80, bearing at one end against the diaphragm nun and at the opposite end against the wall of the housing. The spring thus urges the diaphragm resiliently in the direction of the reciprocative output shaft 82.

The motor housing 76 is supported by a bracket 88 which is mounted on the coupling adapters and 72. The end of the bracket opposite the motor housing forms a protective shield for the adjacent end of the valve slide 50, when the slide is moved to closing position.

A flexible air line 90 is connected at one end to the coupling 20 and at the opposite end to the motor housing 76 for communication with the chamber 78. A second flexible air line 92 is connected at one end to the motor housing for communication with the chamber 78, and its opposite end is connected to a control valve 94 preferably mounted adjacent the spray nozzle 28.

The valve 94 may be a simple two-way valve which, in one position of adjustment by its operating handle closes the connected end of the air line 92. Air under pressure from the container 10 thus is delivered through the air line 90 to the motor chamber 78. This causes the diaphragm 74 to be moved toward the left, against the resistance of the resilient spring 86, resulting in movement of the valve slide 50 to the open position in which the valve slide aperture 52 registers with the threaded bore in the valve body 46. It will be understood that the opposite motor chamber 80 containing the spring would be open to the atmosphere, as by means of an opening through the housing. In a second position of adjustment of the valve the airline 92 is communicated with the atmosphere through the exhaust outlet 96. The air pressure in the motor chamber 78 thus is reduced to atmospheric, whereupon the spring 86 urges the diaphragm 74 toward the right and thus the valve slide 50 is moved to closed position.

In the preferred embodiment illustrated, the valve 94 is a standard three-way valve. A third flexible air line 98 is connected at one end to a third port in the valve and at its opposite end to the motor housing 76 for communication with the chamber 80 which contains the spring 86. In this arrangement the chamber 80 is sealed from the atmosphere. In one position of adjustment of the valve the connected end of the air line 92 is closed and the connected end of the air line 98 communicates with the atmosphere through'the exhaust outlet 96. In this position of adjustment of the valve, air under pressure is delivered from the container 10 through the air line 90 to the motor chamber 78, causing the diaphragm 74 to be moved toward the left against the resistance of the spring 86. This movement of the diaphragm effects movement of the valve slide 50 to the open position in which the aperture 52 registers with the threaded bore in the valve body 46.

In a second position of adjustment of the valve the connected ends of the air lines 92 and 98 are communicated with each other. Air under pressure from the container 10 thus is delivered to both of the motor chambers 78 and 80 to provide equal pressure on both sides of the diaphragm 74. The resilient spring 86 thus operates to move the diaphragm toward the right, whereupon the valve slide 50 is moved to closed position.

The illustrated arrangement of the three-way valve is preferred over the aforementioned two-way valve,

since it does not continually exhaust air under pressure to the atmosphere while the valve slide is held in the closed position.

Although the control valve 94 may be positioned closely adjacent the air motor, it preferably is positioned adjacent the nozzle 28 since the flexible delivery hose 30 usually is quite long and thus the operator is stationed a considerable distance from the container 10. The valve thus functions to control operation of the air motor conveniently from the remote position of the operator.

As in the embodiment illustrated in FIGS. 1-3, the valve body 46 and slide 50 are located in the arrangementillustrated in FIG. 4, behind the spray nozzle 28 in an area of minimum flow velocity of air under pressure. Thus, the same advantages are obtained by this latter arrangement. In addition, the arrangement of FIG. 4 may be provided with standard sandblasting equipment merely by uncoupling the delivery pipe 36 from the elbow 34 and interposing the assembly of valve body 46, coupling adapters 70, 72 and air motor.

It will be understood by those skilled in the art that various changes in the size, shape, number and arrangement of parts described hereinbefore may be made without departing from the spirit of this invention.

Having now described our invention and the manner in which it may be used, we claim:

1. In combination with sandblasting and like spraying apparatus including a nozzle having inlet and outlet ends, a source of fluid pressure, and delivery tube means communicating the nozzle with the source of fluid pressure, a nozzle control valve comprising a. a unitary valve body having therethrough a longitudinal bore having upstream and downstream ends and a transverse valve guide opening substantially normal to and intercepting said bore intermediate the ends thereof,

b. a slide member mounted slidably in said guide opening and having an aperture therethrough, the slide member being reciprocative in the guide opening between one position of adjustment wherein the said aperture registers with said bore and another position of adjustment wherein the slide member intercepts and closes said bore, and

c. coupling means on the body for communicating the upstream end of the bore with the source of fluid pressure and the downstream end of the bore with the inlet end of the nozzle.

2. The combination of claim 1 wherein the coupling means includes internal threads on the body surrounding said bore, and threaded connector means engaging said internal threads on the body on opposite sides of the slide member and slidably engaging the opposed faces of the slide member to restrict the passage of fluid pressure radially outward between said slide member and connector means.

3. The combination of claim 2 wherein the threaded connector means comprises a threaded inlet end portion of the nozzle and a threaded collar connected to the outlet end of the delivery tube means.

4. The combination of claim 1 wherein the delivery tube means includes a plurality of interconnected sections and the coupling means comprises a pair of adapters connecting the adjacent free ends of sections of the deli er tube means to o osite en 5 of said bore.

5. Tle combination 0 claim 1 i ncluding fluid pressure motor means having reciprocative output means connected to the slide member for reciprocating the latter selectively between said positions of adjustment.

6. The combination of claim 5 wherein the source of fluid pressure is a container for air under pressure, the fluid pressure motor is an air motor, and control means connects the air motor to the container for activating the motor selectively to reciprocate the slide member between said positions of adjustment.

7. The combination of claim 6 wherein the delivery tube means is flexible and of substantial length, whereby the nozzle may be moved to positions remote from the container, the air motor is located adjacent the container, and the control means includes adjustable valve means mounted adjacent the nozzle, and flexible tubing communicates the valve means with the container and air motor.

mmno 0043 

1. In combination with sandblasting and like spraying apparatus including a nozzle having inlet and outlet ends, a source of fluid pressure, and delivery tube means communicating the nozzle with the source of fluid pressure, a nozzle control valve comprising a. a unitary valve body having therethrough a longitudinal bore having upstream and downstream ends and a transverse valve guide opening substantially normal to and intercepting said bore intermediate the ends thereof, b. a slide member mounted slidably in said guide opening and having an aperture therethrough, the slide member being reciprocative in the guide opening between one position of adjustment wherein the said aperture registers with said bore and another position of adjustment wherein the slide member intercepts and closes said bore, and c. coupling means on the body for communicating the upstream end of the bore with the source of fluid pressure and the downstream end of the bore with the inlet end of the nozzle.
 2. The combination of claim 1 wherein the coupling means includes internal threads on the body surrounding said bore, and threaded connector means engaging said internal threads on the body on opposite sides of the slide member and slidably engaging the opposed faces of the slide member to restrict the passage of fluid pressure radially outward between said slide member and connector means.
 3. The combination of claim 2 wherein the threaded connector means comprises a threaded inlet end portion of the nozzle and a threaded collar connected to the outlet end of the delivery tube means.
 4. The combination of claim 1 wherein the delivery tube means includes a plurality of interconnected sections and the coupling means comprises a pair of adapters connecting the adjacent free ends of sections of the delivery tube means to opposite ends of said bore.
 5. The combination of claim 1 including fluid pressure motor means having reciprocative output means connected to the slide member for reciprocating the latter selectively between said positions of adjustment.
 6. The combination of claim 5 wherein the source of fluid pressure is a container for air under pressure, the fluid pressure motor is an air motor, and control means connects the air motor to the container for activating the motor selectively to reciprocate the slide member between said positions of adjustment.
 7. The combination of claim 6 wherein the delivery tube means is flexible and of substantial length, whereby the nozzle may be moved to positions remote from the container, the air motor is located adjacent the container, and the control means includes adjustable valve means mounted adjacent the nozzle, and flexible tubing communicates the valve means with the container and air motor. 